In the related art, a hidden hinge is used in a part of an apparatus which is opened and closed, e.g., a door or lid of the apparatus. For example, a door hinge of an apparatus is mounted such that it is not visible on the exterior of the apparatus when the door is closed (or opened).
Specifically, a hidden hinge has a pair of arms attached to, for example, a door and a door frame, and the two arms are connected by a rotating pin which constitutes a rotational axis of the door. The arms are contained in respective recesses on end faces of the door and the door frame when the door is closed (or opened) and the end faces consequently adjoin each other.
The use of such hidden hinges allows furniture and the like to be designed more elegantly.
Techniques associated with hidden hinges having an automatic closing function have been also proposed (for example, see JP-A-2007-046269 (Patent Document 1)).